Nongrounded transmission line



y v1,645,643 L. H. CROOK NONGROUNDED TRANSMISS ON LINE Oct. 18, 1927.

Filed Oct. 2l. 1926 @13 dnbu/ 4 @Hozney' Patented Oct. 18, 1927.

UNITED STATES PATENT OFFICE.

LOUIS H. CROOK, F WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR 0F ONE-HALF TO HERMAN JAKOBSSON, OF TAKOMA PARK, MARYLAND.

NON GROUNDED TRANSMISSION LINE.

Application led 0ctober21, 1926. Serial No. 143,207.

My invention relates to electric transmission lines in general but more particularly to lines of high voltage and has for its object to arrange the lines in such a manner that all a accidents from shocks, caused by Contact with baie conductors, are avoided.

Another object resides in the fact that interference between two separate lines is prevented by the application of the present inventioii so that telephone, telegraph or radio a wire carried on poles, as one conductor;

and the `round constitutes the other conductor. If now the wire should break and contact with a body standing on the ground, said body will experience a shock when the current passes theretliru, and this shock may be fatal as many thousands of volts may be )il carried over the wire.

Taking now the same examplel and supposing that one of the conductors, the ground, could be slit open and wrapped around the other conductor, the wire, but without touching the latter, then an ideal condition would prevail, where it would be perfectly safe to touch the ground or negative conductor even if the positive conductor or wire should be broken and contact with the negative conductor, because the latter protects the former so that the `Jositive conductor cannot be reached from the outside.

, Now the present invention aims at creating this ideal condition, practical solutions of which being described in the following description and illustrated in the accompanying drawing,

Figure 1 is a diagrammatic, perspective view of a non-grounded electric line forming the subject matter of the present 4invention Figure 2, a diagrammatic view and partial section of an ignition system for an automobile;

Figure 8, a plan view of a detail, and

Figure 4, a diagrammatic View and partial section of a similar arrangement for an X-ray tube.

`Referring first to Fig. 1 on the drawing, this shows a general application of the invention to any type of electric transmission line, and reference numeral l0 represents a chamber enclosed on all sides and preferably lined with a good conductor such as copper o r .other metal. Numeral 11 is another similarly constructed and lined chamber. Instead of lining the chambers they may be made entirely of metal. A. copper lined or metal tube 12, connects the two chambers. A conductor or transmission wire 13, is enclosed in the tube,but completely insulated as at 14 from its walls as well as from the chamber walls. Any doors or windows ,in the chambers should be wired and no other openings permitted of any large size except holes so small that no leakage or induced etfects are possible.

The primary or sending chamber contains any kind of electric generating mechanism, such as agenerator, dynamo, battery, radio transmission set, high tension coil set for X-ray work or auto-transmission set 0r the like, which in/the following will be designated as the generator and in Fig. 1 is.

denoted by reference numeral 15. This generator is placed in the middle of the chamber so as to be free from the walls or else insulated from them. In case'an external inotor, such as a hydraulic or steam turbine, is used for supplying mechanical energy to the generator7 this energy may be transinitted thru a shaft 6 into the chamber 10, care being taken that the shaft is properlv insulated.

One of the conductors 16, the negative one for instance, is connected with the wall or lining of the chamber as at 17 and it should be noted that this is not grounding as commonly understood, because the current will not pass thru to the earth but it corresponds in ope-ration to the so called ground. The positive conductor 18 is connected to one end of the wire or cable 13. In the special case of radio-telegraphy this wire would serve as antenna, while the metallic lining of the chamber 10 and the tube 12 wouldcorrespond to the ground. The receiving instrument 19 which may be a radio receiving set, is also positioned in the middle of the secondary chamber 11 or insulated from its walls to which it, however, is connected as at by a negative conductor 21, while a positive conductor 22 connects with the wire 13. By this arrangement, electric current can thus be sent from the generator 15, thru conductors and wire 18, 13 and 22 to the instrument 19 and back to the generator thru conductor 21, the liningof the chamber 11, tube 12, chamber 10 and the conductor 17.

There is absolutely no' necessity for a ground with the earth since all the electric energy is confined within the space enclosed by t e negative, metallic conductor, that is to-say, the lining of the chambers 10, 11 and the tube 12.

In Fig. 2 is shown the application of myinvention to a Ford coil. As before, the pr1- mary chamber 2,5 and the tube 26 are metallic or co per lined and a battery 27, properly ins ated from the walls but electrically connected therewith by a conductor 28, as at 29, is placed in this chamber. The positive conductor 30v connects the battery 27 with the coil 31, which with its negative conductor 32, thru the commutator 33, connects with the lining or wall of the chamber 25. Boththe coil 31 and the commutator 33 are suitably insulated from the chamber walls.

The coil 31, thru the positive conductor 34, connects vwith one end of the Wire 35 which runs thru the tube 26 but is insulated therefrom as at 36. `The tube or its lining is secured to the metallic part of the spark plug 37, making a completely enclosed space from the chamber to the spark plug with the exception of the opening at the lower end of the spark plug over which a metallic screen or plate is stretched as at 38. The wire 35 runs thru the porcelain or dielectric 39 and ends with a spark point 40 between which and the screen 38 the spark gap is formed. The spark plug is preferably insulated as at 41 from the cylinder walls.

It should be particularly noted that the battery 27 is enclosed in the chamber, so that the complete electric energy disturbance is internal, in the apparatus.

High tension is now produced by the coil between the wire 35 and the metal lining 26, and when the gas passes thru the screen 38 from the combustion chamber it will be ignited by a spark at the gap 38-40. All changes of electric energy are internal. The action of the spark plug is accordingly the same as in ordinary arrangements but has no effect on wireless or other electric apparatus that happens to be in its vicinity.

In Fig. 3 the invention is shown as used for an X-ray tube. In this case a metal box 45 forming a closed chamber is also used.

It conta-ins the usual high voltage mechanism including generator with coils 46 insulated from the chamber walls. The generator is actuatedV from any mechanical source of power, externally of the box, thru a drive shaft 47 properly insulated from the chamber walls or made of insulatin mw terial. The X-ray tube 48 is practica y in the same box being placed in the tubular extension 49 which is also metallic and closed at lts end 53 and has a downwardly directed, funnel sha ed aperture 50, over which the usual metalic screen 51 is stretched. The tube 48 is supported in the metallic extension 49 by insulations 52.

A ne ative lead 54 from the high voltage coils o the enerator 46 connects with the walls. of the ox 45 and the positive lead 55 running thru the insulations 56 in the metallic extenslon 49, connects with one end of the X-ray tube 48, while the lead 57 connects the other end of the X-ray tube 48 with the metallic tube 49.

By this arrangement the current runs from the generator coil at 46y over the insulated w1re 55 to the X-ray tube 48 and returns to the generator thru the lead 57, the metallic walls of the extension tube-.and the box 45 and the negative lead 54.

The radiant energy emanating from the surface of the thus excited'X-ray tube passes out thru the inverted funnel 50 to the body to be treated. Since, however, the wire 55 1s completely enclosed and only the box or metalhc tube 49 can be reached from the outside, no shock or other electric effect will be felt by either physician. or patient when touching the metallic box ortube. Or in other words, an electric circuit' cannot be formed between any external' points of the apparatus; that is to say the apparatus has what 1s known amongst physicists as an external' equipotential surface.

It is to be understood that the invention as here described is not limited to the details of construction disclosed and shown and that .these may be varied widely without departing from the spirit of the invention as defined by the claims.

I claim:

a 1. In a non-grounded electric transmission llne, a closed metallic chamber, a generator of electric energy in said chamber, a receivmg instrument in the chamber, both said generator and said instrument being suitably insulated from the metallic chamber, an insulated lead from one pole of said generator connecting with the corresponding pole of sald instrument, and other leads connecting the other poles of the generator and the instrument respectivel with the metallic chamber, substantially as set forth.

2. In a non-grounded electric transmission line, a closed metallic chamber, a generator of electric energy in said chamber suitably insulated therefrom, a metallic extension from said chamber, a receiving instrument suitably insulated in said metallic extension, an insulated lead from one pole of said generator to the corresponding pole of the instrument, and return leads from the other poles of said generator and instrument respectively connecting with the metallic walls of the chamber and its extension.

3. In a non-grounded electric transmission line, a closed metallic chamber, a substantially closed metallic extension on said chamber, an insulated generator of electric energy in said chamber, external means for actuating the generator havingsuitably insulated driving connection therewith, a vacuum tube suitably insulated in said metallic extension, an insulated lead connectincorresponding poles of the generator and t e vacuum tube, and return leads connecting the other poles of the generator and the vacuum tube respectively with the walls of the chamber and the metallic extension, substantially as set forth.

4. An apparatus of the class described having an external, eqhuipotential surface, an electric transmission line enclosed in the apparatus and suitably insulated from the walls thereof and comprising a generator, a receiving instrument and a conductor between corresponding poles of the enerator and the instrument, the Walls of t e apparatus forming the return lead between theother poles of the instrument and the generator, substantially as set forth.

In testimony whereof I alix my'signature.

LOUIS H. CROOK. 

